1. Field of the Invention
The invention relates to the clearing of grease by means of a grease solvent, in particular with enzymes and bacteria as the grease solvent and for the clearing of drainage pipes and grease traps.
2. Background of the Invention
The incidence of grease in different businesses is quite considerable. This applies, for example, in slaughterhouses, sausage and meat product factories, restaurants, fish processing plants, industrial undertakings in which oils and fats are processed and barrel-washing plants. The incidence of grease is seen as a significant problem. As an example, reference is made to the description xe2x80x9cIn Situ Bioremediation of Food-Service Waste Greasexe2x80x9d by Bobby F. Dowden.
According to DIN 4041 a grease trap is prescribed for these businesses so that any grease introduced does not get into the public sewer network/drainage system.
There are also corresponding regulations in other countries. The separated grease must be removed regularly. Even today, the grease in the grease trap is sometimes still removed by skimming off. Skimming off is a very unpalatable task. Added to this are hygiene problems in the grease trap, above all with animal and vegetable fats. Finally, the skimmed-off grease has to be disposed of.
Dowden""s description already refers to the use of enzymes for the degradation of grease. There has been a biological alternative to manual cleaning for several years.
Grease-degrading bacteria and enzymes are measured out into the drainage pipe as a solution in an aqueous nutrient solution. These convert the grease into harmless solids, which can pass into the drainage system without any problems. This technique is described, for example, in U.S. Pat. No. 5,225,083 and likewise in U.S. Pat. No. 4,925,564, U.S. Pat. No. 4,237,003, U.S. Pat. No. 4,810,385, U.S. Pat. No. 4,670,149, U.S. Pat. No. 4,882,059, U.S. Pat. No. 5,171,687, German Patent No. 3906124, European Patent No. 0178931A1, European Patent No. 185528A2.
Enzymes and bacteria occur naturally. They are to be found on an appropriate culture medium. Perishable goods can be used in the search for and isolation of suitable enzyme and bacterial strains. Amongst these are meat and sausage. A greater or lesser number of enzymes and bacteria can be found on the surviving meat and sausage samples. These bacteria can be isolated and propagated in incubators until a technically useable quantity of enzymes and bacteria have been produced.
Starch, amongst other things, is suitable as a nutrient for the enzymes and bacteria. The propagation of the enzymes and bacteria is very successful in the presence of damp and moderate warmth.
The use of enzymes and bacteria in an aqueous nutrient solution is an advantage. However, the technique has not been widely implemented. This is due to the fact that the technique used up till now leaves much to be desired in practice.
The greatest deficiency is the relatively low efficiency in comparison with traditional chemical pipe cleaning agents and grease solvents.
An enzymatic cleaning agent for drains in the home and in commerce is known from Federal Republic of Germany Patent Publication DE-A-3906124. Here, use is made of enzyme mixtures made from pectinases, amylases, cellulases, polygalactoses, lipases and proteases. When common cleaning agents are prepared in liquid form, provision is made to preserve the enzymes until they are used, preferably with salts of sorbic acid and benzoic acid. When the enzymes come to be used, the preservative must be removed once more. This is achieved using enzyme-tolerant tensides. The cleaning agent was developed in 1989 and has not been generally accepted up to the present day.
The same is true of the cleaning agent known from the International Patent Publication WO 97/07190. Here too, the use of enzymes for the cleaning of milk residues is proposed. Before being used for cleaning, the enzymes are dissolved in water for some time and also heated.
Notwithstanding this, the invention seeks to retain the enzyme technique as this technique promises ecological advantages.
In this regard, the invention turns to an older idea. According to this, a solution/suspension containing enzymes is fed at intervals into the drainage pipe or into a grease trap. This idea is based on a preventative degradation of the grease before the build-up of grease leads to a problem in operation. However, this technique has not yet been adopted in practice.
The object of the invention is thus to develop the enzyme technique further. In doing so, the invention starts from the consideration of reducing the transportation and storage volumes.
According to the invention, this object is accomplished by a process for the clearing or cleaning of grease and/or fat by means of a grease solvent with enzymes and bacteria in an aqueous form as the grease solvent and for the clearing of drainage pipes and/or grease traps, characterised in that the grease solvent is produced in situ by combining dry concentrate and water, the water and the dry concentrate first being put into an activator container and activated there, and subsequently introduced into the drainage pipe and/or the grease trap.
The grease solvent made from enzymes and bacteria is supplied and stored in a dry state and is prepared in situ by combining with water, the water and the dry concentrate first being fed into an activator container where they are activated and subsequently fed into the drainage pipe and/or the grease trap. In this case, in situ means in the grease trap or optionally before the grease trap in the direction of flow, if possible immediately at the point where the grease enters.
Advantageously, the introduction of grease solvents can also be used to prevent a damaging build-up of grease in the drainage system without a grease trap so that the installation of a grease trap can be omitted, where this is permissible. The introduction of grease solvents then takes place preferably as close as possible to the point at which the grease enters the drainage system, at the latest at the point where a significant deposition of grease from the waste water is to be expected, this being the grease trap when fitted or the point at which a grease trap would most sensibly be positioned.
The amount of dry concentrate in relation to a liter of water is between 4 and 100 grams, for example. At the same time, the possible mixing in of a filler material is of considerable importance. The filler material can be sawdust.
The dry concentrate is preferably obtained by freeze-drying and not by heating the nutrient liquid in which the enzymes and bacteria are bred, because the enzymes and bacteria can only be subjected to low levels of heat. Advantageously, the nutrient used for breeding the enzymes or bacteria remains in the concentrate when drying so that it is only necessary to add water/moisture to again activate the enzymes and bacteria.
The process according to the invention is based on the knowledge that the grease solvent in the aqueous solution only makes up a small percentage of it. By reducing the transportation and storage to a dry concentrate, the costs for packing and delivery are dramatically reduced. While conventional liquids are delivered by lorry or carrier on account of their volume and weight, the dry concentrate according to the invention can be transported by post with a very great absolute cost advantage due to its low weight in spite of higher specific transport costs. The result is that the process according to the invention exhibits great advantages.
With less of an economic advantage, it is also possible to supply a liquid concentrate and to dilute it in-situ with water. However, this technology (fluid technology) is not comparable with the use of dry concentrate (dry technology) because, with fluid technology, comprehensive cooling of the concentrate must take place during storage and transportation. Otherwise an unwanted activation of the enzymes and bacteria would occur. The further capability of the enzymes and bacteria to survive then depends upon an adequate supply of nutrients. By necessity, the supply of nutrients in the liquid concentrate is soon used up, so that the enzymes and bacteria soon become unusable if they are activated during storage and transportation.
The term dry concentrate does not exclude residual moisture according to the invention. The greater the degree of drying, the less is the danger of an unwanted activation of the enzymes and bacteria.
In a further embodiment of the invention, the combining of the dry concentrate and water takes place close to/immediately at the point where the grease solvent is introduced into the waste water, so that a suspension or a solution is formed. At the same time, the necessary preparation time is taken into account, if necessary by advancing the preparation with respect to the time of introduction. In particular, the preparation time includes the activation time for the enzymes and bacteria and also a time to dissolve/distribute the dry concentrate. The time taken to dissolve in water is shorter the finer the granules of dry concentrate are. As an option, the fineness can be increased by mechanical pulverisation. Grinding is a suitable form of pulverisation.
The preferred process for producing the concentrate from a nutrient liquid is freeze-drying. Different particle sizes occur if the shape formation is uncontrolled during freeze-drying. This can be helped by grinding, however.
Oversized particles can also be avoided by a controlled definition of the shape. This can take place during or after the freeze-drying by means of pelletisation. Pellets are produced between two rollers, for example. The surfaces of such rollers are profiled accordingly, i.e. provided with appropriate depressions. The concentrate is squeezed into these depressions. Particularly suitable shapes for pelletising with rollers are lentil shapes. The corresponding depressions in the surfaces of the rollers are dome-shaped.
An alternative pelletising process includes the squeezing of the starting material through nozzles. The resulting strand of material is granulated (pulverised).
In practice, material with pre-determined dimensions is obtained most of the time both when pelletising using rollers and when pelletising with nozzles followed by granulation. However, more or less fine granules are also obtained from the edges/burrs and broken pieces of pellet material. Preferably, the unwanted granules (undersized granules) are sieved off or separated in other ways from the wanted granules by screening.
Screening has even greater importance in the grinding process mentioned above. Here, not only undersized granules but preferably also oversized granules are screened out. The oversized granules are subjected to a further grinding process.
Preferred pellet sizes and corresponding coarse granules have a diameter of from 2 to 4 mm.
In all the pelletising processes, residual moisture in the dry concentrate is a great advantage in producing and maintaining the shape. If a greater degree of dryness is desired, the pellets are subjected to further drying.
The activation starts in water. A time of at least 0.5 hours is required for activation. As defined by the invention, activation means the multiplication of the enzymes and bacteria until the grease solvent exhibits the desired grease-degradation capacity.
The larger the proportion of concentrate in the water, the quicker a sufficiently effective grease solvent will be available. As a rule, activation times of more than 24 hours are not envisaged.
It is preferred that the concentrate is dissolved in water as this remains stable without any special measures being taken. When producing a suspension or solution a uniform distribution of the concentrate in the suspension or solution can be guaranteed in the well-known manner with the help of an agitator. Such measures can be dispensed with if the suspension or solution is produced a short period of time before the planned introduction of the grease solvent so that there is no fear of a disadvantageous separation/deposition of the concentrate. Slight separations/deposits will be carried away with the grease solvent when it is poured out. The time limits for separation can be determined by a small number of trials.
As an alternative or in addition, the liquid in the activator container used for making the suspension or solution can be agitated before the introduction of the grease solvent, thus swirling up the deposits that have formed.
The suspension or solution produced according to the invention can be introduced in the same manner as the usual liquid agents.
The suspension or solution produced in situ is preferably introduced intermittently. In doing so either specific time intervals are maintained or optionally the time intervals can be chosen to suit the incidence of grease. The incidence of grease can be measured with a flow-measuring device, for example. The measurement can be limited to measuring whether there is any flow at all. The measurement can also establish the order of magnitude of the flow. With the aid of a computer, the desired quantity of grease solvent can then be calculated relatively accurately and can be used to control the dosing. The dosing can include a volumetric and/or a weight-related proportioning of the dry concentrate and/or the grease solvent.
As long as the major part of the grease collects in the grease trap, it is an advantage to adjust the quantity of grease solvent so that only a small amount of grease solvent or even none at all immediately overflows flows the grease trap and flows unused into the system.
Wherever a grease trap with a sump in which drainage water can collect is not fitted, the quantity of grease solvent is preferably adjusted so that there is just sufficient and not excessive coating of the channel surfaces or drainage pipe surfaces that are contaminated with grease. Optionally, the dosing of the grease solvent can also take place solely on a time basis and independently of the magnitude of the flow.
The timing of the dosing can be chosen in a number of ways. In restaurants, for example, the introduction of grease solvent can take place after the midday meal and when the kitchen closes for the night. In doing so, a quantity of grease solvent can be introduced that is matched to the incidence of grease determined by experience or if necessary by trial and error. The quantity of grease solvent required can be determined by trials, for example, by changing the quantity/increasing the quantity/reducing the quantity and by comparing the incidence of grease in the grease trap in the trials with the earlier incidence of grease if necessary.
Particularly favourable cleaning results can be expected at times when business has ceased. At these times, the longest activity time is available for the grease solvent to do its work before the grease solvent is washed away by the next lot of waste water.
As described above, grease deposits can be effectively countered even without the use of measuring devices.
Furthermore, the more frequent instigation of dosing/introduction of grease solvent according to the invention is an advantage for the business. This counteracts deposits in the unit.
A time switch, for example, in the form of a clock whose switching intervals can be adjusted, is suitable for the simplified introduction of grease solvent according to the invention without the use of a measuring device. Such time switches should preferably have several switching intervals.
Different types of apparatus can be considered for the dosing of the dry concentrate devices with linear dosing movements and devices with circular dosing movements.
The dry concentrate is preferably measured out from a storage container by means of a dosing drum into the water intended for the solution or suspension. The dosing drum can have one or more recesses/pockets into which the dry concentrate flows under gravity from above and, after the drum turns, falls out again due to gravity. Each pocket can be sized in such a way that a single filling is sufficient for the production of the desired suspension or solution. The pockets in the drum can also be sized in such a way that the filling and emptying of several pockets or several filling and emptying processes are required in order to measure out the quantity of concentrate needed for a desired suspension or solution. With such a measuring device, it is possible to take the requirements for different quantities of concentrate into account without any problems.
When there is a single pocket in the dosing drum, a periodic rotation of the drum through 180 degrees is required to bring the drum from a vertical filling position into the emptying position vertically beneath it. In the vertical position the filling and emptying conditions are optimum. Usable filling conditions and emptying conditions are also still present with deviations of 30 degrees from the vertical.
It is an advantage if the dosing drum runs between the filling position and the emptying position in an enclosed housing jacket, which prevents unwanted emptying and/or if the dosing drum stops in a particular position. This can be the emptying position or the filling position, or a position in between. When there are several pockets on the circumference of the dosing drum, the rotation of the drum between two emptying processes is shorter.
As an alternative to the dosing drum, a cell wheel can also be used. In contrast to the dosing drum, the cell wheel has only thin walls between two pockets. The thin walls impose increasing demands on the control of the wheel and on the seals. In a normal cell wheel there are problems of accuracy and problems of moisture penetrating the concentrate storage container.
For this reason, the cell wheel according to the invention preferably only has limited application, namely when the pockets between two adjacent walls have a small volume so that a large number of pockets have to be filled and emptied to achieve a desired quantity of concentrate. With a low pocket volume, positioning errors/control errors in the cell wheel and the difficulties resulting from these with the seals of the cell wheel are alleviated because there is now only a dependence on how much concentrate has already accidentally poured out of the first pocket intended for a dosing process and how much more concentrate is added from the pocket following the last pocket to be emptied to give the desired quantity of concentrate.
In contrast to the cell wheel, with the dosing drum there are significantly larger areas of the circumference that can be used as sealing surfaces and which guarantee a good seal even with substantial control tolerances, because the sealing lips are always in contact with the surface of the circumference.
A stepper motor is of advantage for the drive to the dosing drum, the minimum switching step being less than or equal to the smallest rotation of the drum between two emptying processes or between two filling processes.
The rotation of the drum can be different depending upon the number of pockets on the circumference of the drum and the method of operation.
In the case of a single pocket, each switching step can be a 180-degree rotation. When the speed of rotation is low and several filling and emptying processes are required to deliver the desired quantity of concentrate, one switching step can include several revolutions without intermediate stops.
Advantageously, the invention opens up the possibility of using the same dosing drums or cell wheels for different applications and adapting the dosing by changing the number of filling and emptying cycles.
It is an advantage as regards the dosing drum if the motor is provided with a step control or if a pulse-controlled stepper motor is used. The control is preferably electronic and includes the measurement of speed and/or the angle of pivoting. A motor that can turn both clockwise and anticlockwise and/or a speed-controlled motor opens up further advantages.
With such a controllable drive the dosing drum can be returned to the filling position after every emptying process or brought to a position between the filling opening and the emptying opening, or to particular emptying positions or filling positions in which the pocket sits at an angle forming an incoming or outgoing slope. Furthermore, the tipping process can be affected by changing the speed of tipping. This can be used to reduce water splashes.
The drum housing optionally has a continuous shaft running through it. The dosing drum then sits as a rotating sealing mechanism in the shaft.
A small motor is recommended for the drive to the dosing drum, the movement of which is reduced by a gear.
As an option, the gearing can also be designed as a controller for the dosing drum by using a rotating toothed ring, which is moved by a pinion on the drive shaft of the motor. At the same time the toothed ring can act as a cam controller if it is of sufficient size for fitting cams.
Additional seals are preferably provided for the dosing drum, which are intended to prevent the ingress of moisture into the storage container. The seals can be made up of customary O-rings and straight sealing strips. Seals made in one piece can also be used, however.
The seals on the outlet opening of the shaft have the greatest efficiency. Here, the seals are provided in the gap between the drum and the housing.
When pellets or coarse-grained dry concentrate are used, rubber seals with their resilient capability can fling out the individual granules that penetrate the gap around the seal. When using dry concentrate in powder form, seals made from thermoplastic material, which do not have the same resilient capability as rubber, can also be used.
Another alternative for dosing is offered by the linear feeder.
A linear feeder according to the invention moves the dry concentrate in a straight line.
A cylinder with a reciprocating piston rod with two pistons mounted on it is provided for this purpose. The cylinder is connected to the storage container in such a way that the piston rod can drive into the dry concentrate when the cylinder opens. It is an advantage if the dry concentrate is extracted from the storage container from below. The dry concentrate can then run into the cylinder under gravity. At the same time, the cylinder is closed at the bottom by the second piston.
After the cylinder has filled, the piston rod with the two pistons is withdrawn until the piston away from the storage container exits from the cylinder. In this way the cylinder opens and the dry concentrate can pour down into the activator container.
It is an advantage if the cylinder is connected tightly to the storage container.
The pistons then simultaneously form a seal for the storage container. The seal is important to keep the dry concentrate dry. A one-piece construction of the cylinder and the storage container is an advantage.
Optionally the connection with the activator container can also be sealed or it can be more or less open. It is an advantage if the cylinder protrudes into the inlet opening of the activator container. This prevents any dry concentrate coming out of the cylinder falling beside the inlet opening of the activator container.
Optionally the pistons are of a usual construction.
Alternatively, it is envisaged that the pistons can be formed by two sealing discs.
The piston facing the storage container can be designed in the form of a disc. For the other piston, a hat-shaped or mushroom-shaped or cone-shaped design is preferred, so that this piston has sloping sides for the dry concentrate to run off.
In addition, the lower sealing disc can be in the form of a membrane so that it is totally flexible and forms a seal by contacting the inner wall of the cylinder with its sealing lips.
The other piston constructed as a sealing disc can also be in the form of a membrane or be equipped with sealing lips. If necessary, the upper sealing disc is additionally equipped with an O-ring.
The seal is increased if, between two dosing processes, the piston rod remains in a position where both pistons are in the cylinder.
The two sealing discs can be manufactured with the piston rod as a plastic injection molding. This is extremely cost-effective for large batches.
The piston rod can be driven from above through the storage container. There is also no objection to having a closed casing for the storage container if the casing is sufficiently flexible and the piston rod can be engaged with the casing from above, or if the piston rod drive can be connected with the piston rod indirectly via the flexible casing in a different way.
The drive can also be arranged at the side and can also reach into the cylinder through a slot provided for the purpose.
The drive can also be taken from below. Indeed, for this purpose the drive can be arranged beneath the cylinder and even built into the activator container. However, it is preferable for a rod feeding out of the cylinder from below to be provided, which leads to a drive arranged at the side.
The drive can be in the form of a toothed belt drive or a linear motor drive or a reciprocating cylinder drive or a spindle drive or a toothed rack drive. The same dosing cycles can be carried out with the linear feeder according to the invention as with the dosing drum.
The production of the suspension or solution takes place in particular in an activator container in which water and concentrate are brought together. The activator container can be round, in shape which is favourable for a movement, in this case a rotary movement, of the bath. As an option, the activator container can also be provided with inserts, which promote a swirling motion of the contents of the container. The movement can be produced by introducing the water through nozzles or, if necessary, also by mechanical agitators.
It is an advantage to arrange at least one nozzle in the area where the concentrate is mixed with the water.
The concentrate can be added before or after the water or at the same time as the water.
The concentrate and the water can be added differently, e.g. the concentrate can be added after injection of a first quantity of water and before injection of the remaining quantity of water. Preferably at least one nozzle is provided at the top in the activator container. The nozzle can be fixed under the rim of the container. It is advantageous for the nozzle to be mounted at an angle.
The objective is either to spray or cover as large an area as possible and/or to create a swirling motion in the suspension or solution. Nozzles or groups of nozzles in the form of slits are best suited for spraying large areas uniformly. An intensive movement of the bath is an advantage in creating an intensive swirling motion. This movement of the bath is preferably achieved by a single nozzle or several nozzles grouped together.
At least one nozzle can also be arranged at the container outlet. Deposits are a particular nuisance at the container outlet. For this reason, the container outlet is rinsed clear by the nozzle positioned there. The nozzle provided there can be arranged and can work in the same or a similar way to that provided at the top on the rim of the container so that a swirling motion of the deposits is produced before the container outlet is opened.
The quantity of fresh water required to activate the nozzles is taken into account when previously filling the activator container, i.e. the quantity of water is reduced by the amount of fresh water required for the later actuation of the nozzles (preliminary filling level). In this way an overflow of the activator container is avoided.
A further function of the nozzles is to clean the activator container after emptying by the addition of further water.
As an option, the mixing water for the production of the suspension/solution is measured out so that, after emptying, only an acceptable amount of dilution of the suspension or solution takes place due to the water running out from the cleaning of the activator container. This applies to the introduction of the suspension or solution into a drainage pipe in need of cleaning.
When the suspension or solution is introduced into a grease trap that is to be cleaned, the quantity of cleaning water, at least in the case of large-volume traps, is not important.
Different solutions are available for adjusting the filling level, the maximum filling level and the preliminary filling level. A common and well-proven solution is the use of level switches. As such, float switches are typically used as level switches. According to the invention, the use of capacitive switches, which are mounted externally on the activator container, is preferred. Mounting them externally reduces the number of internal parts in the activator container and the need for maintenance.
Another solution is a timer circuit. The timer circuit is a possible solution because under constant water inflow conditions it is possible to measure particular filling times both to reach the maximum filling level and also to reach the preliminary filling level. It is true that not all water inflow conditions remain absolutely constant. The water pressure can vary considerably. However, the measurable times remain within relatively close limits, so that these times can be used via a time switch for switching off the water feed. As an option, it is possible to use a common time switch with an adequate number of switching contacts for both these switching operations and for the switching operations associated with the concentrate feed.
An overflow is provided in the event that a fault should occur in switching off the water feed. As an option, the overflow is combined with the container outlet. An advantageous embodiment provides for a hollow plug as a closure for the container outlet. The hollow plug is of such a length that its upper end coincides with the maximum filling level and any excess water can run out through the top of the hollow plug.
The hollow plug is optionally raised and guided by means of a rod or by a ring-shaped lifting mechanism arranged on the foot of the plug. A magnet is suitable as a lifting drive as only a relatively short stroke is required to actuate the container outlet.
For the hollow plug to be effective, a seal is necessary at its lower end.
The hollow plug, which acts as an overflow, is fitted with a cone-shaped cover at the top to prevent a loss of dry concentrate through the hollow plug/overflow. The conical shape is intended to deflect any dry concentrate that falls onto it.
If this feature is not desirable, it can be avoided by moving the outlet opening of the storage container to one side so that it is no longer above the inlet opening of the activator container. Conversely, the inlet opening can also be moved. There is then an eccentricity in relationship to the center.
In another variation of the invention, an advantageous activator container is created. Here, the invention starts from the knowledge that it is an advantage for the activation of the enzymes and bacteria if the mixture remains in the activator container for a period of time and at the same time is subjected to movement. Indeed, a circulating motion is favourable and can be produced by an agitator and the form of construction described above. An additional vertical circulation of the bath is even better.
As an option, the speed of movement can be limited at the same time. This is based on the knowledge that some enzymes and bacteria cannot survive and are destroyed, or are at least stunted in their growth, when subjected to high mechanical loads at high pump speeds.
According to the invention, provision is made in such cases to reduce the usual pump speed from 3000 rpm. Depending upon the construction of the pump, the maximum speed for sensitive enzymes and bacteria can be 1500 rpm, for more sensitive enzymes and bacteria 500 rpm and for highly sensitive enzymes and bacteria 100 to 300 rpm.
A pump with variable speed is of particular advantage here.
Additional advantages result from the use of a controlled feed of air, as is known per se. The correct amount of air can be determined by means of a small number of trials by increasing and reducing the amount of air supplied.
Even if the desired mixture has already been achieved in a short period of time, e.g. within one minute, the desired growth of the enzymes and bacteria dictates a longer stay in the activator container. As a rule the duration of the stay is at least 0.5 h but not longer than 24 h.
As an option, the vertical movement can be realised by drawing off the suspension/solution from near the bottom and reintroducing the liquid near the top of the container.
It is preferred to produce the vertical movement according to the invention by subjecting only the liquid in the container to a drive in the vertical direction. According to the invention, a pump rotor/impeller/vaned wheel, which in itself is unsuitable, arranged at the bottom of the container, can be used for this purpose. Such pump rotors/impeller wheels are in themselves unsuitable for vertical movement as they form a circulating agitator and produce only a rotation of the liquid in one plane.
However, according to the invention, a vertical movement is produced because the container according to the invention is equipped with inserts or profiles that direct the flow. The inserts or profiles preferably form ribs that run vertically. According to the invention, the height of the ribs is chosen in proportion to the dimensions of the container. For circular containers, the height of the ribs or their web height is at least 10% and at most 50% of the radius of the container. Greater web heights are actually possible and to a great extent do not cause any harm, but are viewed as being uneconomic.
The ribs extend along the inner wall of the container and preferably start at the bottom of the container. At the top there can be a gap between the ribs and the lid of the container. The gap should preferably be at least xc2xc of the diameter of the container and the length of the ribs a maximum of xc2xe of the diameter of the container.
The rotor/impeller wheels have a suction opening in the middle. The suspension/solution that enters is thrown radially outwards due to the rotational motion. A vacuum is created in the middle at the suction opening. The suspension/solution is sucked in from above and drawn downwards. At the same time, the suspension/solution that is forced radially outwards is steered upwards to flow back to the center at the surface of the bath or below the surface of the bath. A rolling flow is set up.
The rotor/impeller wheels according to the invention form pumps arranged internally. Externally arranged pumps can also be used in place of these pumps or can work together with the internally arranged pumps.
A rolling flow according to the invention is also set up with the pump rotor/impeller wheels described above without inserts to guide the flow by an angled arrangement of the activator container.
The diameter of the container can vary within wide limits. Preferred embodiments have a container diameter of 200 mm. With the rotor/impeller wheel arrangement according to the invention, at the bottom of the container, the container length/height is not more than 8 times the diameter of the container. Favourable ratios are given by a ratio of 1:1 of container diameter to container length or height. At the same time, the quantity of water required according to the process and the constructional outlay as well as the outlay on bearings for the diameter of the pump rotor/impeller wheels must be taken into account. For this reason, the invention concentrates on one (at the most three) rotor/impeller/wheel diameter, e.g. 200 mm, and achieves the required container volume by appropriately increasing or decreasing the container length/height. The rotor/impeller/vaned-wheel diameter is preferably from 100 to 300 mm.
A further parameter of the pump rotor/impeller/vaned wheel according to the invention is its height above the bottom face of the container. In a preferred construction the height is from 10 to 30 mm, e.g. 20 mm. The height can vary depending upon the height of the container. The ratio of the height of the pump rotor/impeller/vaned wheel to the height of the container is at least 1:30 and at most 1:3.
After the desired activation/growth of the enzymes and bacteria in the activator container has been reached, the suspension/solution is supplied to the point of its intended use. To ensure that emptying takes place in a short time, the suspension/solution can optionally be pumped out. The pump can have a further pump rotor/impeller/vaned wheel for other purposes. The further pump rotor/impeller/vaned wheel is preferably used for circulating or mixing the bath to accelerate the growth.
Advantageously, the mechanisms of both pumps can sit on the same shaft, i.e. the pump rotor/impeller/wheel for the circulation/mixing of the bath in the container and the pump rotor/impeller/wheel for pumping out the suspension/solution or emptying sit on one shaft/axle. A fixed arrangement is thus possible without a clutch or gears if the mechanism of the pump for extracting/emptying the suspension is arranged beneath the mechanism of the pump for extracting or mixing the suspension and if the mechanisms cause a flow effect in only one direction of rotation. The flow effect in only one direction of rotation occurs by freewheeling on the shaft in the non-flow direction or by means of a special shape of the mechanisms. Such a shape is formed for example by vanes in the shape of an arc, which extend from the shaft/axle in a radial direction to the wall of the container. The shaft/axle can be formed by a tube and/or a pin. The vanes extend on the arc from the middle to the outer edge, the front of the arcs defining the flow direction and the rear the direction of rotation that does not have any flow effect. The radius of the arcs is at least equal to one quarter of the rotor/impeller/wheel diameter and preferably less than half of the rotor/impeller/wheel diameter.
The front sides of the arcs of the lower pump mechanism preferably point in the opposite direction of rotation in relation to the front sides of the arcs of the upper pump mechanism.
Advantageously, the vanes are stabilised by a common, ring-shaped disc. The ring-shaped disc has an opening in the center through which the suspension/solution is sucked out and in the preferred embodiment experiences a radial motion at the vanes towards the outer wall of the container.
The outflowing suspension/solution can be collected at the outer wall by means of a ring-shaped channel and fed to an outlet.
It is an advantage if the ring-shaped disc lies at the top of the lower pump mechanism and forms a channel for the suspension/solution to be emptied. This effect can be increased if the container wall seals as tightly as possible with the pump mechanism or the disc as appropriate via the ring-shaped channel while maintaining the necessary play. The same applies to the ring-shaped disc on the upper pump mechanism. There, the formation of the channel effects an improvement of the circulation capacity. The ring-shaped disc for the lower pump mechanism, which is arranged at the top of the lower pump mechanism, also contributes to the formation of the channel for the upper pump mechanism.
If the outside diameters of the two pump mechanisms are equal, the circulation flow at the outer edge of the upper pump mechanism is established by means of an adequate gap with the inner wall of the container. The gap also exists if the seal with the lower pump mechanism mentioned above is formed by a web running around the circumference of the container wall and directed inwards.
Due to the formation of the channel according to the invention, it is possible to turn the two pump mechanisms simultaneously. When operating the pump mechanism for circulating or mixing the suspension/solution, the pump mechanism for emptying is turned with it in the direction in which it does not effect any flow. The reverse is true when the pump mechanism for emptying is operated and the pump mechanism for circulating or mixing is turned with it.
As an option, the two pump mechanisms sit so as to be able to rotate on a common tube. At the same time, one mechanism can also form a pin/retainer on which the other mechanism sits.
As an option, one pump mechanism also has a tube, or one pump mechanism is also connected to a tube, on which the other pump mechanism sits.
The tube can be used as an air feed. Just small quantities of air are sufficient to activate the enzymes and bacteria. These small quantities of air are optionally drawn in by the vacuum forming in the middle of the pump mechanism for circulating or mixing. At the same time, the quantities of air can be limited by using passages of small cross section. In the case of an activator container with a diameter of 200 mm and with an equal height, for a mixture of 30 gr of enzymes and bacteria in water and with air being drawn in by means of the resulting vacuum, an entry/exit opening of just 1 mm diameter can be sufficient.
Advantageously, individual and several components used in accordance with the invention can also be used independently of the production of the suspension/solution in situ. For example, the dosing system according to the invention can also be used to dispense the dry concentrate directly into a grease trap.
The production of the suspension/solution according to the invention can also be used to introduce grease solvent into a drainage pipe remotely.
In the same way, the production of the suspension/solution according to the invention can be arranged before or after a siphon used as an odour seal.
Or, the mixing device can be used in conjunction with dosing scales.
Or, the production of the suspension/solution can be used to dilute and dispense liquid concentrate.
Or, the production of the suspension/solution can be used wholly or in part in other areas of life, e.g. for the preparation of beverages from dry concentrate in the foodstuffs area or, in the chemical area, for mixing solid materials in liquids or for the production of solutions.
In as far as figures for diameter are given above and in other embodiments containers with non-circular cross sections are used, a circular cross section with the same surface area as that of the other configuration is defined and used as a reference basis for the diameter figures.
Further characteristics of the invention are described in the claims.
The above-discussed embodiments of the present invention will be described further hereinbelow. When the word xe2x80x9cinventionxe2x80x9d is used in this specification, the word xe2x80x9cinventionxe2x80x9d includes xe2x80x9cinventionsxe2x80x9d, that is the plural of xe2x80x9cinventionxe2x80x9d. By stating xe2x80x9cinventionxe2x80x9d, the Applicant does not in any way admit that the present application does not include more than one patentably and non-obviously distinct invention, and maintains that this application may include more than one patentably and non-obviously distinct invention. The Applicant hereby asserts that the disclosure of this application may include more than one invention, and, in the event that there is more than one invention, that these inventions may be patentable and non-obvious one with respect to the other.